Radiative environments can induce defects in the exposed materials, whose accumulation leads to defect structure transformations and optical quenching. Therefore, their role is crucial for the fabrication of devices. β‐Ga 2 O 3 :RE system seems attractive for prospective optoelectronic applications. In this research, structural defects created in the crystal lattice upon Sm ion implantation in (010)‐oriented β‐Ga 2 O 3 and the recovery after annealing are investigated. Channeling Rutherford backscattering spectrometry (RBS/c) supported by McChasy simulations and room‐temperature photoluminescence (RT‐PL) spectroscopy are applied to study the structural and optical changes, respectively. The studies reveal the existence of two different randomly displaced atoms (RDA)‐types of defects in the implanted zone and the optical inactivity of Sm‐dopant ions. Rapid thermal annealing (RTA) in argon at 800 °C for 0.5 min results in the removal of deeply located defects, while the defects closer to the surface are not influenced significantly. RT‐PL measurements demonstrate the strong luminescence in the visible and ultraviolet regions of the spectrum.